Adjustment assembly and substrate exposure system comprising such an adjustment assembly

ABSTRACT

The invention relates to a substrate exposure system comprising a frame, a substrate support module for carrying a substrate, an exposure apparatus for exposing said substrate, and adjustment assembly for adjusting the position of the exposure apparatus with respect to the substrate support module. The adjustment assembly comprises a hydraulic actuator, a hydraulic generator and a conduit, wherein the conduit interconnects said hydraulic actuator and said hydraulic generator for forming a hydraulic system. The exposure apparatus, the frame, the adjustment assembly and the substrate support module are arranged as parts of a series of mechanically linked components. A first part of said series of mechanically linked components comprises the exposure apparatus, and a second part comprises the substrate support module. Said hydraulic actuator is arranged between said first part and said second part. Preferably the hydraulic actuator comprises a first bellows and the hydraulic generator comprises a second bellows.

BACKGROUND

The invention relates to a mechanical adjustment assembly and to systemsadjusted thereby. In particular a mechanical adjustment assembly for usein systems comprising a series of mechanically interlinked components,in particular systems having components in difficult to approachenvironments such as but not limited to exposure systems, more inparticular systems or mechanical arrangements comprising a frame, afirst module connected to said frame, a second module carried by orconnected to said frame. The invention further relates to a method foradjusting the position and/or orientation of the first module withrespect to the second module.

Lithography systems are arranged for projecting a pattern onto a target,such as a silicon wafer. State of the art lithography systems expose thetarget by means of electromagnetic radiation, in particular light, morein particular UV light, or by means of charged particles, in particularelectrons, for projecting said pattern on the target.

Inspection systems are arranged for exposing a target or sample by meansof electromagnetic radiation, such as in an optical microscope, or bymeans of charged particles, in particular electrons in an electronmicroscope, and analyzing radiation or charged particles resulting frominteraction of the exposure radiation with the target in order toacquire information from the target.

WO 2013/034753 describes a lithography system or an inspectionapparatus, in particular a charged particle multi-beam lithographysystem. The components of the lithography or inspection system forgenerating and projecting the beams, are typically arranged in a column,and will be referred to herein as the ‘exposure apparatus’. The systemdescribed in WO 2013/034753 comprises a support frame and a supportelement for holding the exposure apparatus. The support element isconnected to the support frame by means of at least one spring element,for at least partially isolating the support element from vibrations.

A disadvantage of this known system is that in use and over time, creepcan occur inter alia in the spring element, which results in a deviationof the position of the support element with respect to the support framefrom the set position. As a consequence, the position of the supportelement, and the position of the exposure apparatus held by said supportelement, with respect to a target to be exposed and/or inspected, canalso deviate from an optimum position in the system. This has an adverseeffect on the performance of the system, specifically on the exposure oftargets.

Another exposure apparatus is known from US2009/0086178. This systemcomprises a light source and an illumination optical system whichilluminates a reticle. A barrel shaped projection optical systemprojects an image of the reticle onto a substrate on a wafer stage. Theprojection optical system is connected to a frame by means of threesuspension support mechanism. Further three drive mechanisms areprovided between the frame and projection optical system. Each drivemechanism includes a voice coil motor that drives the projection opticalsystem in a radius direction of the barrel, and a voice coil motor thatdrives the projection optical system in the direction of an optical axis(the Z-axis direction). With three drive mechanisms, the projectionoptical system can be moved in the direction of six degrees of freedom.

A disadvantage of this known system is that the actuators which move theexposure apparatus are included as contactless motors and are thuslimited in the load that can be carried.

A further problem associated with substrate exposure systems is thenegative influence of vibrations on substrate exposure. Systemsaddressing such problems by active damping are known, e.g., from2008/0218720 A1 and US 2008/0013058 A1.

US 2008/0218720 A1 describes an exposure apparatus configured to projectlight from an original to the substrate. The exposure apparatus includesa projection optical system which includes an optical element and adriving unit configured to move the optical element. The apparatus isarranged for reducing vibrations due to the reaction force accompaniedby driving the optical element for correcting aberration ormagnification change of the image plane. The projection optical systemfurther includes a support mechanism configured to support theprojection optical system via a gas spring, a control unit configured togenerate a driving signal for the driving unit, and an actuatorconfigured to apply a force, in accordance with the driving signal, tothe projection optical system in a direction opposite to the directionof the reaction force accompanied by the action force from the drivingunit to the optical element.

US 2008/0013058 A1 describes a pneumatic spring apparatus provided withgas chambers, which are filled with a gas at a prescribed pressure andprovided with an adjustment apparatus for adjusting a temperature changedue to the capacity change of the gas chamber. The pneumatic springapparatus can be included in an anti-vibration apparatus for supportingan object with a gas pressure, e.g. supporting a substrate stage in anexposure apparatus.

A further disadvantage of substrate exposure systems in general, andlithography or microscopy systems in particular, is that they are highlycomplex systems in which a large number of components are arranged in acompact and/or enclosed configuration. In such systems it is difficultto adjust the position of a component, in particular when the componentis not readily reachable from the outside of the system.

It is an object of the present invention to overcome or at leastminimize the effect of one or more of these disadvantages or to at leastprovide a substrate exposure device comprising an alternative adjustmentassembly and/or method for adjusting the position of a component of saidsubstrate exposure device.

SUMMARY OF THE INVENTION

According to a first aspect, the present invention provides a mechanicaladjustment assembly for adjusting a position of a first part of a seriesof mechanically linked components with respect to a second part of aseries of mechanically linked components,

wherein said mechanical adjustment assembly comprises a first bellows, asecond bellows and a conduit, wherein the conduit interconnects saidfirst bellows and said second bellows for forming a hydraulic system,

wherein said first bellows is arranged between said first part and saidsecond part of said series of mechanically linked components, whereinthe second bellows is arranged spaced apart from said first bellows, andwherein the first bellows is arranged to be actuated by said secondbellows.

The first bellows can be actuated and/or driven by the second bellowsfor adjusting the position of the first module and the second modulewith respect to one another. Since the first and second bellows arearranged spaced apart from one another, the first bellows can bearranged in a system, for example at a location which is difficult toaccess from outside the system, enabling position adjustment at thelocation which is difficult to access, using the second bellows whichcan be located outside the system.

In an embodiment, the second bellows is provided with a drive unit,arranged to compress or expand the second bellows for actuating thefirst bellows. The drive unit preferably comprises a motor, such as astepper motor. Alternatively, the second bellows may be compressedand/or expanded via a manually operated arrangement.

In an embodiment, the system comprises at least one sensor for measuringa position of said first part with respect to said second part of saidseries of mechanically linked components or a change in position of thefirst part of said series of mechanically linked components with respectto the second part of said series of mechanically linked components.This enables verifying the relative position of the first second partsof the series of mechanically linked components. By transmitting thesensor signals to a control unit connected to the drive unit, therelative position of the first and second parts can be automaticallyadjusted.

The mechanical adjustment assembly may be used in a substrate exposuresystem. Accordingly, in an embodiment said series of mechanically linkedcomponents comprises an exposure apparatus, a frame, the mechanicaladjustment assembly and a substrate support module. Preferably, saidfirst part of said series of mechanically linked components comprises atleast the exposure apparatus, and a second part of said series ofmechanically linked components comprises at least the substrate supportmodule.

According to a second aspect, a method is provided for adjusting aposition of a first part of a series of mechanically linked componentswith respect to a second part of a series of mechanically linkedcomponents, comprising:

providing a mechanical adjustment assembly comprising a first bellows, asecond bellows and a conduit, wherein the conduit interconnects saidfirst bellows and said second bellows for forming a hydraulic system,

arranging said first bellows between said first part and said secondpart of said series of mechanically linked components,

arranging the second bellows spaced apart from said first bellows, and

actuating the second bellows, thereby causing actuation of the firstbellows, such as to adjust the position of the first part ofmechanically linked components with respect to the second part of theseries of mechanically linked components.

The method of the second aspect may be performed using the mechanicaladjustment assembly according to the first aspect.

In an embodiment, the method comprises controlling the actuating of thesecond bellows based on signals from at least one sensor measuring aposition of said first part with respect to said second part of saidseries of mechanically linked components or a change in position of thefirst part of said series of mechanically linked components with respectto the second part of said series of mechanically linked components.

According to a third aspect, the invention provides substrate exposuresystem comprising:

a frame,

a substrate support module for carrying a substrate, which substratesupport module is connected to said frame,

an exposure apparatus, wherein the exposure apparatus is connected tosaid frame and is arranged for exposing the substrate carried by thesubstrate support module, and

an adjustment assembly for adjusting the position of the exposureapparatus with respect to the substrate support module, wherein theadjustment assembly comprises a hydraulic actuator, a hydraulicgenerator and a conduit, wherein the conduit interconnects saidhydraulic actuator and said hydraulic generator for forming a hydraulicsystem, wherein the exposure apparatus, the frame, the adjustmentassembly and the substrate support module are arranged as parts of aseries of mechanically linked components, wherein said series ofmechanically linked components comprises a first part comprising atleast the exposure apparatus, and a second part comprising at least thesubstrate support module, and wherein said hydraulic actuator isarranged between said first part and said second part of said series ofthe mechanically linked components.

The mechanical adjustment assembly of the first aspect may be used inthe substrate exposure system of the third aspect. Technical effects andadvantages of the first aspect apply correspondingly to the thirdaspect, and vice versa.

Embodiments described in the following may be applied also to the firstand/or second aspect.

In the substrate exposure system of the present invention, the exposureapparatus, the frame, the adjustment assembly and the substrate supportmodule are arranged as parts of a series of mechanically linkedcomponents. In this interconnected arrangement, the hydraulic actuatoris arranged between the exposure apparatus and the substrate supportmodule. The hydraulic actuator is arranged to be actuated by thehydraulic generator for adjusting the position of the exposure apparatusand the substrate support module with respect to each other. At least inuse, the hydraulic actuator, the conduit and the hydraulic generator arefilled with a hydraulic liquid, preferably water, to form a hydraulicsystem.

The substrate exposure system of the present invention comprises ahydraulic system which allows adjusting the position of a component inthe system by means of the hydraulic actuator, which hydraulic actuatoris remotely controlled and/or actuated by the hydraulic generator. Thehydraulic generator is preferably arranged to be readily accessible fromthe outside of the system. Accordingly, the adjustment assembly of thepresent invention makes it easier to adjust the position of a component,for example the exposure apparatus and/or the substrate support module,inside the substrate exposure system, and allows adjusting the positionof a component inside the substrate exposure system without requiringaccess into said system.

Until now, hydraulic systems have not been used in substrate exposuresystems such as lithography or microscopy systems, for adjusting theposition of a component, in particular a component which is arrangedwithin the system. The inventor has however realized that the hydraulicsystem in the substrate exposure system of the invention is highlysuitable for adjusting deviations or drift of a position and/ormisalignment, for example due to creep, which is usually a relativelyslow process.

In addition, the adjustment assembly according to the present inventionprovides a hydraulic system that enables the adjustment assembly tocarry a high load and providing a stiff support for the exposureapparatus and/or the substrate support module.

Further, the hydraulic system in the mechanical adjustment assembly andthe substrate exposure system of the invention provides a remote controland/or actuation of the adjustment assembly without bringing electricalsignals and/or electrical fields inside a system in which is it applied,such as the substrate exposure system. This is highly advantageous forsubstrate exposure systems which comprise a charged particle exposureapparatus, such as an electron beam lithography system or an electronmicroscope, since electric or magnetic fields generated by leadscarrying electrical signals can disturb the trajectory of the chargedparticles in such a substrate exposure system. Such disturbance has anadverse effect on the performance of such substrate exposure systemcomprising a charged particle exposure apparatus, specifically on theexposure of targets. In the substrate exposure system according to thepresent invention, this adverse effect is, at least partially,circumvented by using a hydraulic system for adjusting the position ofthe exposure apparatus with respect to the substrate support module.

In an embodiment, said hydraulic actuator comprises a first bellows.Although said hydraulic actuator may also comprise a hydraulic cylinderfor example, the use of a first bellows is advantageous because thehydraulic fluid is better confined within the bellows and a chance ofleakage of hydraulic liquid is reduced since a bellows does not haveparts that telescope out as in a hydraulic cylinder.

In an embodiment, said hydraulic generator comprises a second bellows.Although said hydraulic generator may also comprise a hydraulic pump forexample, the use of a second bellows is advantageous because thehydraulic fluid is better confined within the bellows and a chance ofleakage is reduced.

Using first and/or second bellows as a hydraulic actuator and/orhydraulic generator, respectively, provides a simple hydraulic system inwhich the hydraulic fluid is confined within a substantially constantvolume as provided by the internal volume of the first and secondbellows and the conduit. When the second bellows is compressed, thisinduces a flow in the conduit which has the effect of expanding thefirst bellows. Likewise, expanding the second bellows induces anopposite flow in the conduit thus compressing first bellows.

In an embodiment, the second bellows is provided with a drive unit,preferably a mechanical linear drive unit, wherein the drive unit isarranged to compress or expand the second bellows for actuating thefirst bellows. The mechanical linear actuator is arranged forcompressing and expanding the second bellows, and thus to remotelycontrol an expansion and compression of the first bellows.

In an embodiment, the mechanical linear actuator comprises a manuallyoperable actuator, such as an adjusting screw. In an alternativeembodiment, the drive unit comprises a motor, preferably a steppermotor. The motor is arranged to compress and/or expand the secondbellows for actuating the first bellows. This enables automatedadjustment of the position of the exposure apparatus with respect to thesubstrate support module, for instance using a control system.Preferably, said control system is connected to a sensor for measuring aposition of the exposure apparatus or the support element, with respectto said frame. This allows to measure a deviation of the position of theexposure apparatus, and to control an adjustment of the position of theexposure apparatus with respect to the substrate support module on thebasis of the measured deviation.

In an embodiment, the system comprises at least one sensor for measuringa position of said first part with respect to said second part of saidseries of the mechanically linked components, or for measuring a changein position of said first part of said series of mechanically linkedcomponents with respect to the second part of said series ofmechanically linked components. This should be construed to encompassthat the sensor is arranged to measure a relative position or change ofthe position of the first part of the mechanically linked componentswith respect to the second part of the mechanically linked components,and/or is arranged to measure a relative position or change of theposition of the second part of the mechanically linked components withrespect to the first part of the mechanically linked components.

In an embodiment, the sensor is arranged for measuring a verticalposition of said first part with respect to said second part of saidseries of the mechanically linked components, or for measuring a changein a vertical position of the exposure apparatus with respect to thesecond part of said series of mechanically linked components. Thisembodiment is particularly suitable for a system wherein a springelement provides a flexible connection between the first part of theseries of mechanically linked components, including e.g. the exposureapparatus, and the second part of the series of mechanically linkedcomponents. Such flexible connection provides flexibility insubstantially the vertical direction of the exposure apparatus withrespect to the second part of the series of mechanically linkedcomponents, in particular with respect to the frame segment which ispart of the second part of said series of mechanically linkedcomponents. The substantial vertical flexibility is preferably arrangedfor dampening vibrations transmitted from the floor onto which theexposure system is placed. The relatively quick changes in the positionof the exposure apparatus with respect to the substrate support moduledue to these vibrations can be counteracted by actuators in thesubstrate support module. In addition to the possible occurrence ofvibrations, the spring element is constantly subjected to asubstantially vertical force due to the weight of at least the exposureapparatus. This vertical force may induce creep in the spring element,which is typically a slow process. A deviation in the distance betweenthe exposure apparatus and the substrate support module due to thecreep, in particular the vertical deviation in position, is measured bythe sensor. When a certain deviation in position is measured, thehydraulic actuator arranged between the frame and said spring elementcan be actuated for moving the exposure apparatus with respect to theframe to suitably counteract the deviation in position. Accordingly, theadjustment assembly of the present invention, in particular thehydraulic system thereof, is typically suitable for compensatingdeviations in the position of the exposure apparatus with respect to thesubstrate support module due to slow processes, such as creep.

In an embodiment, the sensor is a capacitive sensor. A capacitive sensorallows to accurately measure the position of the support element withrespect to the frame and thus with respect to rest of the system, inparticular with respect to the substrate support module, whilstproviding a compact and economical option. The capacitive sensor allowsto accurately measure the distance between the support element and theframe. In an embodiment, the system comprises multiple capacitivesensors which are positioned in an arrangement to measure the distancebetween the support element and the frame, and a tilt and/or inclinationof the support element with respect to the frame.

In an embodiment, the exposure apparatus is moveably connected to theframe by means of at least one spring element. In an embodiment, thefirst part of said series of mechanically linked components comprisessaid spring element.

In a preferred embodiment, the hydraulic actuator is arranged betweenthe frame and said spring element, and is preferably arranged for movingthe exposure apparatus with respect to the frame. Accordingly, thehydraulic actuator is arranged to counteract a deviation from a setand/or predetermined position of the exposure apparatus with respect tothe frame, which deviation is typically induced by creep of the springelement.

In another preferred embodiment, the hydraulic actuator is arrangedbetween the frame and the substrate support module. In this embodiment,the hydraulic actuator is arranged for moving the substrate supportmodule with respect to the frame to counteract a deviation in therelative position of the exposure apparatus with respect to thesubstrate support module.

In an embodiment, the hydraulic actuator comprises an end stop,preferably an internal end stop. In an embodiment the first bellowscomprises said end stop. This end stop limits the movement of thehydraulic actuator, in particular of the first bellows. Preferably theend stop is arranged to substantially prevent contact between theexposure apparatus and the substrate support module. Accordingly the endstop is arranged to limit the movement of the exposure apparatus towardsthe substrate support module, or vice versa. When the hydraulic actuatorreaches said end stop, the exposure apparatus and the substrate supportmodule are still spaced apart and thus are not in contact with eachother. In addition or alternatively, the end stop is arranged to providea fixed support when the hydraulic system of the adjustment assembly isdrained. In this case, the end stop places the support element in aservice position when the hydraulic system is emptied, preventing damageto the support frame, the exposure apparatus and/or the first bellows,for example during transport.

In an embodiment, said substrate exposure system further comprises ahousing, wherein the exposure apparatus and the substrate support moduleare at least partially arranged inside said housing, wherein thehydraulic actuator is arranged inside said housing and the hydraulicgenerator is arranged outside said housing.

In an embodiment, the housing comprises a wall, and the conduit passesthrough said wall. This allows the hydraulic actuator to be placedinside the chamber, the hydraulic generator outside the chamber. Theconduit connecting the hydraulic actuator and hydraulic generatorextends through the wall, for forming the hydraulic system.

In an embodiment, said housing is arranged to function as a vacuumchamber, wherein the housing is coupled to a vacuum pump for, in use,creating a vacuum pressure inside said housing, preferably wherein atleast the hydraulic actuator is vacuum compatible. The vacuum chamberallows establishing a vacuum environment at least for the part of theexposure apparatus that is arranged inside the chamber, and may alsoprovide shielding from outside influences, such as electrical and/ormagnetic fields. The vacuum chamber provides suitable environment forthe exposure of a substrate in case the substrate exposure systemcomprises a charged particle lithography system or an EUV lithographysystem. In an embodiment, the hydraulic actuator, preferably the firstbellows, is vacuum compatible.

To increase throughput, i.e. the number of wafers exposed per hour inlithography system, a desire exists to efficiently use the spaceavailable in the housing, for example in order to reduce the size of thesystems so that more systems can be arranged in a certain area in anindustrial environment. This efficient use of space available in thehousing results in reduced and limited access to the exposure apparatusenclosed in the housing. The adjustment assembly according to thepresent invention allows the adjustment of the position of the exposureapparatus with respect to the substrate support module by the hydraulicactuator inside the housing, while the actuation of the adjustmentassembly is performed by means of the hydraulic generator on the outsideof the housing.

In an embodiment, the frame comprises a bottom wall, side walls and anupper wall, wherein the substrate support module is arranged on top ofsaid bottom wall, and wherein the exposure apparatus is connected to oneor more of the side walls or to the upper wall. Preferably the sidewalls of the frame are arranged at least partially around the exposureapparatus. Preferably the bottom wall, side walls and upper wall of saidframe are arranged to form a box or part of a box. A frame comprising abottom wall, side walls and an upper wall, in particular when arrangedto form a box or part of a box, can provide a substantially rigidarrangement. When the walls are arranged to form a substantiallyrectangular box, the rigidity of the frame is enhanced in particular dueto the angular arrangement of the various walls of the box and aninterconnection of said walls, which can be used as at least part of theframe for supporting the exposure apparatus and/or the substrate supportmodule. Accordingly at least part of the box is part of the series ofmechanically linked components.

Preferably, the spring element is arranged inside said box or saidbox-shaped frame, in particular between the exposure apparatus and thewalls of the box. The exposure apparatus and the substrate supportmodule are preferably arranged inside said box.

In an embodiment, the conduit passes through one of said bottom wall,side walls and upper wall of said box or said box-shaped frame. Thisallows placing the hydraulic actuator inside the box and the hydraulicgenerator outside the box.

In an embodiment, the box or box-shaped frame is arranged inside saidhousing, and wherein at least one of said bottom wall, side walls andupper wall of said box may be provided with an array of throughopenings. The through openings are particularly suitable when thehousing is arranged to function as a vacuum chamber. The throughopenings are arranged to provide flow path from the inside of the box tothe outside of the box. When the housing is coupled to a vacuum pump andthe vacuum pump is activated for creating a vacuum pressure inside saidhousing, the flow path from the inside of the box to the outside of thebox enables to create a vacuum pressure inside said box.

In an embodiment, at least one of said bottom wall, side walls and upperwall is provided with a shielding layer, wherein said shielding layerpreferably comprises a layer of a μ-metal. The shielding layer isarranged for at least partially shielding a space inside said frame fromexternal magnetic fields, both static and dynamic. This embodiment isparticularly useful for an exposure apparatus using charged particlesfor exposing a substrate.

In an embodiment, the exposure apparatus is arranged inside anenclosure, wherein said enclosure is movably connected to said frame.Said enclosure preferably substantially surrounds said exposureapparatus. In an embodiment, the enclosure is connected to said springelement.

In an embodiment, the enclosure is arranged inside said housing, whereinsaid enclosure comprises at least one wall which is provided with anarray of through openings. In a further embodiment, the enclosure isarranged inside said box. The through openings are arranged to provideflow path from the inside of the enclosure to the outside of theenclosure, analogous to the description above.

In an embodiment, said enclosure is provided with a shielding layer,wherein said shielding layer preferably comprises a layer of a μ-metal,and functions analogous to the shielding layer described above.

In an embodiment, said substrate exposure system comprises threeadjustment assemblies. This enables adjusting the relative positionand/or the relative orientation of the first and second parts of themechanically linked components. In an embodiment, said three adjustmentassemblies are arranged to form a triangle or a triangular configurationaround said exposure apparatus and/or said substrate support module. Inan embodiment, the three adjustment assemblies are connected to and/or(partially) supporting said exposure apparatus and/or said substratesupport module. This provides three degrees of freedom for adjusting theposition and/or orientation of the exposure apparatus and the substratesupport module with respect to each other. In case each one of the threeadjustment assemblies is arranged such that the first bellows provides adisplacement in a substantially vertical direction, the three adjustmentassemblies provide an adjustment in the vertical Z-direction, and a tiltaround the horizontal X and Y axis, providing 3 degrees of freedom.

In an embodiment, the system is a lithography system, wherein theexposure apparatus comprises an optical column of said lithographysystem.

In an embodiment, the exposure apparatus comprises a charged particlebeam optical column. In an embodiment, the exposure apparatus comprisesa multi-beam charged particle optical column. In an embodiment theexposure apparatus comprises a multi-beam charged particle lithographicapparatus or inspection apparatus.

According to a fourth aspect, the present invention provides a methodfor adjusting the position of the exposure apparatus with respect to thesubstrate support module in a substrate exposure system as describedabove, wherein the method comprises the step of:

driving the hydraulic generator for actuating the hydraulic actuatorwhich provides a change in relative position of the said first part withrespect to said second part of said series of the mechanically linkedcomponents.

In an embodiment, said method further comprises the step of measuring aposition of said first part with respect to said second part of saidseries of the mechanically linked components or measuring a change inposition of the said first part with respect to said second part of saidseries of the mechanically linked components.

In an embodiment, said method further comprises the steps of:

-   -   generating a control signal in accordance with said measured        position or change in position, and    -   driving the hydraulic generator in accordance with said control        signal.

The various aspects, embodiments of the various aspects, and featuresdescribed above can be combined.

The various aspects and features described and shown in thespecification can be applied, individually, wherever possible. Theseindividual aspects, in particular the aspects and features described inthe attached dependent claims, can be made subject of divisional patentapplications.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be elucidated on the basis of an exemplary embodimentshown in the attached drawings, in which:

FIG. 1 schematically shows a first example of a substrate exposuresystem according to the present invention;

FIG. 2 schematically shows a second example of a substrate exposuresystem according to the present invention;

FIG. 3 schematically shows an example of a hydraulic system according tothe present invention;

FIG. 4A schematically shows an example of an exposure apparatus for usein the substrate exposure system of FIG. 1 or 2 to provide a multi-beamcharged particle beam lithography system;

FIG. 4B schematically shows an example of an exposure apparatus for usein the substrate exposure system of FIG. 1 or 2 to provide alight-optical lithography system; and

FIG. 4C schematically shows an example of an exposure apparatus for usein the substrate exposure system of FIG. 1 or 2 to provide a chargedparticle beam microscopy system.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 schematically shows a first embodiment of a substrate exposuresystem 1 according to the present invention. The vertical directioncorresponds to the Z-direction, whereas the horizontal directioncorresponds to the Y-direction. The X-direction is perpendicular to boththe Y-direction and the Z-direction and extends into and out of thepaper.

The substrate exposure system 1 comprises a frame 2, a substrate supportmodule 3 for carrying a substrate 5, and an exposure apparatus 4 forprojecting a beam or multiple beams of electromagnetic radiation orcharged particles onto a substrate 5, such as a semiconductor wafer.

The substrate exposure system 1 comprises a housing 11 whichsubstantially encloses the exposure apparatus 4 and the substratesupport module 3. When the exposure apparatus 4 is arranged for usingUV, deep UV (DUV), extreme UV (EUV), X-ray beams or charged particlebeams, the housing 11 is arranged to function as a vacuum chamber,wherein, in use, the housing 11 is coupled to a vacuum pump 6 forcreating a vacuum or reduced pressure inside said housing 11.

Inside said housing 11, the frame 2 is arranged. In the illustratedembodiment, the frame 2 and the housing 11 share a common bottom wall12. The frame 2 further comprises side walls 22, a rear wall 22 b and anupper wall 23. The frame 2 comprises two side walls 22 and a rear wall22 b, which are at a lower side connected to the common bottom wall 12and at the upper side connected to the upper wall 23. The common bottomwall, the two side walls 22, the rear wall 22 b and the upper wall 23are connected to each other to provide a box-shaped frame 2, preferablya rectangular box-shaped frame 2. Alternatively, the side walls 22 canbe arranged spaced apart from each other, and/or the frame may beprovided by a structure formed by rods and/or beams instead of walls.

The side walls 22 and the upper wall 23 may be provided with throughopenings 24 to enable a flow path between the inside and the outside ofthe box-shaped frame 2, to create and maintain a vacuum or reducedinside throughout the inside of said housing 11.

The substrate support module 3 is arranged on the common bottom wall 12.The substrate support module 3 comprises an XY-stage comprising twoX-stage bases 31. Each X-stage base 31 carries an X-stage carriage 32,connected to a respective actuator A1, A2 for driving the respectiveX-stage carriage 32 along the X-stage base 31. On top of said X-stagecarriages 32, a Y-beam 33 is arranged, which bridges the space betweenthe X-stage carriages 32. On top of said Y-beam 33, a Y-beam carriage 34is arranged including actuators (not shown) for driving the Y-beamcarriage 34 along the Y-beam. On top of said Y-beam carriage 34 apositioning device 35 is arranged for moving a chuck 36, carrying thesubstrate 5, in the X, Y and/or Z-direction and in one or morerotational directions Rz, Rx, Ry. The positioning device 35 typicallycomprises electro-motors.

As shown in FIG. 1, the side walls 22 and the rear wall 22 b of thebox-shaped frame 2 are provided with brackets 25, which are rigidlyconnected to their respective wall 22, 22 b. As viewed from the frontside as depicted in FIG. 1, the box-shaped frame 2 is provided withthree brackets 25, one on each left and right side wall 22 as depictedin FIG. 1 and one on the rear wall 22 b.

On top of each of said brackets 25, a first bellows 71 is arranged, forsupporting a first support member 26. The first support member 26 isconnected to a second support member 27 via spring elements 81.Furthermore, dampening elements 82 are arranged between the first andsecond support members. The spring elements 81 and the dampeningelements 82 are arranged for at least partially isolating the secondsupport element 27 from vibrations.

As shown in FIG. 1, the exposure apparatus 4 is arranged on an exposureapparatus frame 41, which exposure apparatus frame 41 is connected tothe second support member 27 by means of a plurality of pendulums rods28. The exposure apparatus 4 may for example be an exposure apparatus asdescribed with reference to FIGS. 4A-4C.

The exposure apparatus 4 is arranged inside an enclosure 42, whichsubstantially surrounds said exposure apparatus 4 and which may beconnected to the exposure apparatus frame 41.

As shown in FIG. 1, the enclosure 42 is arranged inside the box-shapedframe 2. Also the enclosure 42 may comprise at least one wall which isprovided with an array of through openings 43, arranged to provide aflow path from the inside of the enclosure 42 to the outside of theenclosure 42, enabling creating a vacuum also inside said enclosure 42.

In the embodiment of FIG. 1 both the box-shaped frame 2 and theenclosure 42 are provided with a shielding layer 51, 52 for shieldingthe exposure apparatus 4 from magnetic fields, which shielding layer 51,52 preferably comprises a layer of a μ-metal.

As described above, the substrate support module 3 is connected to theexposure apparatus 4 via a series of mechanically linked components.This series of mechanically linked components comprises the commonbottom wall 12 of the box-shaped frame 2, the side walls 22 and rearwall 22 b of the box-shaped frame 2, the brackets 25, the first bellows71, the first support member 26, the spring elements 81 and dampeningelements 82, the second support member 27, the pendulums rods 28, andthe exposure apparatus frame 41.

As discussed in the introductory part of this description, creep canoccur in the spring elements 81, which results in a deviation of theposition of the exposure apparatus 4 with respect to the substratesupport module 3 from the set position.

In order to compensate said creep, the substrate exposure system 1comprises a mechanical adjustment assembly for adjusting the relativeposition of the exposure apparatus 4 with respect to the substratesupport module 3. The mechanical adjustment assembly as shown in FIG. 1comprises the first bellows 71 and second bellows 72, described below,connected to the first bellows 71 by a conduit 73 for forming ahydraulic system. The first bellows 71 are arranged for moving a firstpart of the series of mechanically linked components with respect to asecond part of the series of mechanically linked components. The firstpart of the series of mechanically linked components comprises the firstsupport member 26, the spring elements 81 and dampening elements 82, thesecond support member 27, the pendulums rods 28, the exposure apparatusframe 41, and the exposure apparatus 4. The second part of the series ofmechanically linked components comprises the brackets 25, the sidewalls22 and rear wall 22 b of the box-shaped frame 2, the bottom wall 12 ofthe box-shaped frame 2, and the substrate support module 3. By actuatingthe first bellows 71, the first part of the series of mechanicallylinked components can be moved with respect to the second part of theseries of mechanically linked components.

As shown in FIG. 1 the first bellows 71 are connected to second bellows72 by means of conduits 73. The first bellows 71 are arranged to act asa hydraulic actuator which can be actuated by said second bellows 72,arranged to act as a hydraulic generator. The combination of a firstbellows 71 and a second bellows 72 interconnected by a conduit 73, whichfirst bellows 71, second bellows 72 and conduit 73 are, at least in use,filled with a hydraulic fluid, provides a simple hydraulic system inwhich the hydraulic fluid is confined within a substantially constantvolume provided by the internal volume in the first bellows 71, secondbellows 72 and the conduit 73. When the second bellows 72 is compressed,this induces a flow in the conduit 73 which has the effect of expandingthe first bellows 71. Likewise, expanding the second bellows 72 inducesan opposite flow in the conduit 73 which has the effect of compressingfirst bellows 71.

As schematically indicated in FIG. 1, the conduits 73 are arranged totraverse through a wall of the housing 11 and through the frame 2, forconnecting the first bellows 71 inside the housing 11 to the secondbellows 72 outside said housing 11. The second bellows 72 are readilyaccessible at the outside of the housing 11 and can be actuated at theoutside of the housing 11 in order to activate the first bellows 71inside said housing 11 to move and/or re-adjust the position of theexposure apparatus 4 with respect to the substrate support module 3.Because of the arrangement of three first bellows 71 which are arrangedaround, in particular above, the exposure apparatus 4 in a triangularconfiguration, the three first bellows 71 can move the first supportmember 26 to translate in the Z-direction, to tilt around theX-direction and/or around the Y-direction.

The system 1 is provided with sensors 53, which are arranged to measurethe position or change in position of the enclosure 42, and hence theposition of the exposure apparatus 4, relative to a side wall 22 of thebox-shaped frame 2. The sensors 53 are connected to the outer side ofthe enclosure 42 and measure their distance to the side wall 22 of thebox-shaped frame 2, in particular their distance to a target (not shown)arranged at a fixed position on the side wall 2 of the box-shaped frame2. Alternatively, the sensors 53 can be connected to the inner side ofthe side wall 22 of the frame and measure their distance to the outerside of the enclosure 42. The enclosure 42 belongs to the first part ofsaid series of mechanically linked components, and the side walls 22 ofthe box-shaped frame 2 belong to the second part of said series ofmechanically linked components.

The sensors 53 are arranged for measuring at least a vertical positionor a change in the vertical position of the exposure apparatus 4 withrespect to a fixed position along the side wall 22 of the box-shapedframe 2. The spring elements 81 provide an elastic connection betweenthe exposure apparatus 4 and the frame 2, which elastic connectionprovides a flexibility which is substantial in the vertical orZ-direction. The spring elements 81 are constantly subjected to asubstantially vertical force due to the weight of the second supportmember 27, the pendulums rods 28, the exposure apparatus frame 41, theenclosure 42 and the exposure apparatus 4. This vertical force mayinduce creep in the spring elements 81, which results in a deviation inthe distance between the exposure apparatus 4 and the substrate supportmodule 3, in particular the chuck 36 carrying the substrate 5, whichdeviation is measured by the sensors 53. When a certain deviation inposition is measured, one or more of said first bellows 71 arrangedbetween the frame 2 and said spring element 81 are actuated by actuatingthe corresponding one or more second bellows 72 outside the exposuresystem 1 for moving the exposure apparatus 4 with respect to the frame 2to suitably counteract the deviation in position due to said creep.

Preferably, as schematically shown in FIG. 1, the system 1 is providedwith three sensors 53, one on the left side of the enclosure 42, one onthe right side of the enclosure 42, and one on the back side of theenclosure 42 (not shown). Each one of said sensors 53 is preferablyarranged so that said sensors 53 measures at least a vertical positionalong the Z-axis. The sensors 53 may comprise a further arrangement inorder to measure also a horizontal position along the X-axis and/or ahorizontal position along the Y-axis. For example, each of said sensors53 may comprise two detectors which are arranged substantiallyperpendicular to each other. The sensor 53 shown on the left hand sideof the enclosure 42 in FIG. 1 comprises two detectors for measuring aposition along the X-axis and Z-axis. The sensor 53 shown on the righthand side of the enclosure 42 in FIG. 1 comprises two detectors formeasuring a position along the X-axis and Z-axis. The sensor on the rearside of the enclosure 42 (not shown), comprises two detectors formeasuring a position along the Y-axis and Z-axis. Each of said sensors53 is arranged to measure a position of said sensor with respect to atarget fixed to the side wall 22 and rear wall 22 b of the box-shapedframe 2. However for the adjustment assembly of the present invention,in particular the three sensors 53 for measuring the position along theZ-axis are of importance.

The system 1 is provided with a control unit which is arranged toreceive positional data from the sensor assemblies 53, and which isarranged to control a set of drive units, preferably one for each secondbellows 72, for actuating said drive units to drive the second bellows72 for actuating the first bellows 71 based on the data from the sensors53. Such a control system is schematically shown in FIG. 2.

FIG. 2 shows a second embodiment of a substrate exposure system 1′according to the present invention. In this embodiment the substratesupport module 3 is arranged on top of a third support member 29.Underneath the third support member 29 several first bellows 71′ arearranged, which first bellows 71′ are arranged between the bottom wall21 of the frame 2′ and the third support member 29. The first bellows71′ are connected with the second bellows 72′ via conduits 73′ to forman hydraulic system which allows to move the third support member 29with respect to the bottom wall 21 of the frame 2′.

The first support member 26 is arranged on top of three support posts222. The three support posts 222 are arranged at the corner points of atriangle on top of a frame bottom wall 21, and extend in theZ-direction, substantially perpendicular to the frame bottom wall 21.Preferably, the exposure apparatus 4 is arranged substantially at acenter point of said triangle formed by the three support posts 222.Accordingly, the substrate support module 3 is connected to the exposureapparatus 4 via a series of mechanically linked components. This seriesof mechanically linked components comprises the third support member 29,the first bellows 71′, the bottom wall 21 of the frame 2′, the supportposts 222 of the frame 2′, the first support member 26, the springelements 81 and dampening elements 82, the second support member 27, thependulums rods 28, and the exposure apparatus frame 41.

In order to compensate the creep which may occur in the spring elements81, the substrate exposure system 1 comprises a mechanical adjustmentassembly for adjusting the relative position of the exposure apparatus 4with respect to the substrate support module 3. The adjustment assemblyshown in FIG. 2 comprises the first bellows 71′, the second bellows 72′,and the conduits 73′. The first bellows 71′ are arranged for moving afirst part of the series of mechanically linked components with respectto a second part of the series of mechanically linked components. Thefirst part of the series of mechanically linked components comprises thebottom wall 21 of the frame 2′, the support posts 222 of the frame 2′,the first support member 26, the spring elements 81 and dampeningelements 82, the second support member 27, the pendulums rods 28, theexposure apparatus frame 41, and the exposure apparatus 4. The secondpart of the series of mechanically linked components comprises the thirdsupport member 29 and the substrate support module 3. By actuating thefirst bellows 71′, the second part of the series of mechanically linkedcomponents can be moved with respect to the first part of the series ofmechanically linked components. The first bellows 71′ are arranged toact as a hydraulic actuator which can be actuated by said second bellows72′ which are arranged to act as a hydraulic generator. The combinationof a first bellows 71′ and a second bellows 72′ which are interconnectedby a conduit 73′, provides a hydraulic system, similar to the hydraulicsystem as described with reference to FIG. 1.

As schematically indicated in FIG. 2, the conduits 73′ are arranged totraverse through a wall of the housing 11 for connecting the firstbellows 71′ inside the housing 11 to the second bellows 72′ outside saidhousing 11. Preferably the conduits 73′ are arranged to traverse in asideward direction past the support posts 222 of the frame 2′ forconnecting the first bellows 71′ inside the frame 2′ to the secondbellows 72′ outside said frame 2′. The second bellows 72′ are readilyaccessible at the outside of the housing 11 and can be actuated at theoutside of the housing 11 in order to activate the first bellows 71′inside said housing 11 to move and/or re-adjust the position of thesubstrate support module 3 with respect to the exposure apparatus 4. Inthe example shown in FIG. 2 the first bellows 71′ are arrangedsubstantially directly below the X-stage bases 31.

As shown in FIG. 2, the system 1′ is provided with sensors 53, which arearranged to measure the position or change in position of the enclosure42 relative to a support post 222 of the frame 2′, in the same manner asin the embodiment of FIG. 1. The embodiment in FIG. 2 additionallycomprises further sensors 54, connected to the outer side of the thirdsupport member 29 and/or the X-stage bases 31 and arranged to measuretheir distance to the support posts 222 of the frame 2′. Alternatively,the further sensors 54 can be connected to the inner side of the supportposts 222 of the frame and measure their distance to the outer side ofthe third support member 29 and/or the X-stage bases 31. In particular,the further sensors 54 are arranged for measuring a position or a changein position of the substrate support module 3 with respect to a supportpost 222 of the frame 2′.

The further sensors 54 are arranged for measuring at least a verticalposition or a change in the vertical position of the substrate supportmodule 3 with respect to a fixed position along the support posts 222 ofthe frame 2′.

As described with reference to FIG. 1, the spring elements 81 provide anelastic connection between the exposure apparatus 4 and the frame 2′,which elastic connection provides a flexibility which is substantiallyin the vertical or Z-direction, and are subjected to a substantiallyvertical force which may induce creep in the spring elements 81,resulting in a deviation in the position of the exposure apparatus 4along the support posts 222 of the frame 2′, which deviation is measuredby the sensors 53. When a certain deviation in position is measured, oneor more of said first bellows 71′ are actuated by actuating thecorresponding one or more of said second bellows 72′ outside theexposure system 1′ for moving the substrate support module 3 withrespect to the frame 2′ to provide a substantially similar deviation inposition of the support module 3 along to the frame 2′ as measured bythe further sensors 54 as the deviation in position of the exposureapparatus 4 along the frame 2′ as measured by the sensors 53.

As schematically shown in FIG. 2, but also applicable in the embodimentof FIG. 1, the sensors 53 are coupled to a control unit 9 to supplypositional data of the relative position of the exposure apparatus 4with respect to the support posts 222 of the frame 2′. In addition thefurther sensors 54 are coupled to the control unit 9 to supplypositional data of the relative position of the substrate support module3 with respect to the support posts 222 of the frame 2′. From thepositional data of the sensors 53 and the further sensors 54, thecontrol unit 9 can determine the relative position and/or orientation ofthe exposure apparatus 4 with respect to the substrate support module 3,in particular the chuck 36 which in use carries the substrate 5.

The control unit 9 is coupled to drive units 91, in particular one driveunit 91 for each of the second bellows 72′, wherein each drive unit 91is arranged to compress or expand the corresponding second bellows 72′for actuating the corresponding first bellows 71′. The drive units 91are located outside the housing 11, as are the second bellows 72′.

When the control unit 9 finds a deviation in the relative positionand/or orientation of the exposure apparatus 4 with respect to thesubstrate support module 3 compared to a set position, the control unit9 sends a control signal to one or more of the drive units 91 foractuating said drive units 91 to compress or expand the correspondingsecond bellows 72′ for actuating the first bellows 71′ in order to movethe third support member 29 and the substrate support module 3 in orderto compensate said deviation in the relative position and/or orientationof the exposure apparatus 4 with respect to the substrate support module3. As schematically shown in FIG. 2, the drive unit 91 comprises alinear actuator, wherein the drive unit 91 comprises a motor, preferablya stepper motor, for moving the linear actuator.

The arrangement of a control unit coupled to drive units for each secondbellows can also be used in the first embodiment shown in FIG. 1.

It is furthermore noted, that the present invention can be used withvarious configurations of the frame 2, 2′. In the first embodiment, theframe 2 is a box-shaped frame where the exposure apparatus 4 is carriedby brackets 25 attached to the side walls 22, 22 b. Instead ofpositioning the first bellows 71 on top of the brackets 25 as in thefirst embodiment, the first bellows may also or in addition be providedbelow the substrate support module 3. In the second embodiment, theframe 2 comprises three support posts 222 in a triangular arrangementfor carrying the exposure apparatus 4. Instead of position the firstbellows 71′ below the substrate support module 3 as in the secondembodiment, the first bellows may also or in addition be provided on topof said three support posts 222.

It is furthermore noted that in the embodiment shown in FIG. 2,interconnecting elements 112 are arranged between the housing 11 and theframe 2. Alternatively however, the frame 2 and the housing 11 may sharea common bottom wall as shown in the first example in FIG. 1.

FIG. 3 schematically shows an embodiment of one of the mechanicaladjustment assemblies comprising a hydraulic system according to theinvention. Typically, three such hydraulic systems are used peradjustment assembly. Three hydraulic systems enable the support elementto be adjusted in three degrees of freedom, i.e. the Z direction androtations around the X axis (Rx) and rotations around the Y axis (Ry).The adjustment assembly comprises a first bellows 403. This bellows isplaced between the first and second parts of the mechanically linkedcomponents, in particular inside an exposure system, for example theexposure system of FIG. 1 or 2, or inside an enclosure or housing,schematically represented by the dotted line 110, depending on what isrequired for the system in which the adjustment assembly is placed.

The inner volume of the first bellows 403 is in fluid connection with aconduit 402 for interconnecting with the inner volume of the secondbellows 401. First bellows 403, conduit 402 and second bellows 401 arefilled with a hydraulic fluid, preferably water, for forming a hydraulicsystem. When the second bellows 401 is compressed, the hydraulic fluidflows from the second bellows 401 through the conduit 402 into the firstbellows 403 which has the effect of expanding the first bellows 403.Likewise, expanding the second bellows 401 induces an opposite flow inthe conduit 402, thus compressing the first bellows 403. Thisarrangement enables adjustment of the transfer ratio between the firstand second bellows by varying the diameters and thus the internal volumeboth of the second bellows 401 and the first bellows 403. The ratiobetween the volumes of the bellows will determine the transfer ratio.For a ratio I, when the second bellows 401 is compressed over a distanceS1, the first bellows 403 will expand over a distance S1/I. Conversely,the force F1 required to compress the second bellows 401 over a distanceS1, will result in a force F1*I being exerted at the first bellows 403.It is thus possible to provide a larger or much larger force at thefirst bellows 403 than is applied at the second bellows 401.

The second bellows 401 can be actuated to allow adjustment of a supportelement carried by the first bellows 403, as for example described abovewith reference to the FIGS. 1 and 2. In an embodiment, the secondbellows 401 is actuated with an actuator mechanism 404. The actuatormechanism 404 comprises, for example, a mechanical linear actuator 405which converts a rotary motion into a linear motion M1. The linearmotion M1 can be used to expand or compress M2 the second bellows 401,which in turn provides a compression or expansion M3 of the firstbellows 403. Preferably, a self-locking mechanical linear actuator 405is used, comprising a threaded screw 406 that contacts the secondbellows 401 and is arranged to compress the second bellows 401. Thethreaded screw 405 is preferably arranged to rotate in a threaded nutthat is in a fixed position in relation to the second bellows 401. Thepitch of the threaded screw 405 and nut are such that when therotational force on the screw 405 is removed, the mechanical linearactuator 404 will remain in the set position to maintain the position offirst bellows 403 and the support element it carries.

In one embodiment, the mechanical linear actuator 404 is manuallyactuated. Alternatively, the mechanical linear actuator 404 is actuatedby a motor (not shown), preferably a stepper motor, for driving arotation of the threaded screw 405. The step motor provides themechanical linear actuator with small and discrete steps of adjustment.This enables automated adjustment of the position of the support elementin small increments, for instance using a control system. Since thescrew mechanism in the mechanical linear actuator acts as a forcemultiplier, large mechanical ratios are obtained, up to 1:1000. Further,since an expansion or compression of second bellows 401 will result inan expansion or compression of the first bellows 403 that is I timessmaller, it is possible to accurately control the movement of firstbellows 403. In practice, the adjustment assembly according to theinvention provides several millimeters of travel, whilst being able tobe positioned with micrometer accuracy. During operation, the adjustmentassembly provides a large force at first bellows 403.

When the first bellows 403, conduit 402 and second bellows 401 are madeof steel, it is ensured that the adjustment assembly is of sufficientstiffness. Parts of the adjustment assembly that are not sufficientlystiff act as springs during use, which is undesirable for an adjustmentassembly since this can lead to unwanted movement of the adjustmentassembly, and a change in eigenfrequency which causes the system toresonate. Further, steel conduits and bellows are vacuum compatiblewhich is required when the adjustment assembly is enclosed in a vacuumchamber.

The hydraulic system comprises a bleed valve 309, for filling and/oremptying the system. The bleed valve 309 is preferably included at thelowest point in the hydraulic system, and is preferably placed outsidethe housing 110 of the system.

The first bellows 403 preferably comprises an internal end stop 308 toprevent full compression of the bellows when the hydraulic system isemptied. An external end stop can alternatively be used. The end stop308 places the support element in a service position when the hydraulicsystem is emptied, preventing damage to the support frame, the supportelement and the first bellows. The module further comprises a valve 304a for connecting to a pump 305, preferably a vacuum pump, and a valve304 b for connecting to a hydraulic liquid tank 306. The valves 304 aand 304 b are placed along conduit 302, or may be jointly connected injoint 304. This arrangement allows for controlled filling of thehydraulic system, by first emptying the system through valve 309 whenrequired, pumping the system to a certain vacuum pressure using vacuumpump 305 and filling the system with liquid from tank 306 after pumping.It was found that a vacuum pressure of less than 50 mbar, preferablyless than 10 mbar, is sufficient to fill the system and to ensure thatno air is trapped in the bellows and conduit. Trapped air bubbles act assprings, which is undesirable in a hydraulic system. During use, thepressure in the system is approximately 6 bar. The combination of steelconduits and bellows, pressurized liquid and lack of air in the systemsallows the system to accurately carry and position the components of theexposure system which may be weighing several hundreds of kilograms.

It was found that the adjustment assembly according to the presentinvention can advantageously be applied in various kinds of exposuresystems, such as lithography systems, electron microscopes, waferinspection tools or any system which requires part of the system to beplaced in a known position and/or orientation and which system canexperience drift over time. This drift occurs in the systems even whenno elastic or flexible elements are applied in the system. In suchsystems modules or parts of the system need to be accurately positionedin a chamber, housing or enclosure with limited access. The use of theadjustment assembly according to the invention is thus not limited tolithography systems.

FIGS. 4A to 4C show examples of exposure apparatus for use in, e.g., oneof the systems described with reference to FIGS. 1 and 2 above.

FIG. 4A shows an example of an exposure apparatus for a multi-beamcharged particle lithography system 440 arranged on the exposureapparatus frame 41. The multi-beam charged particle lithography system440 is arranged in modules 441, 442, 443, 444 which can be individuallyinstalled and removed from the exposure apparatus frame 41.

The upper module 441 comprises a charged particle source 445 arranged togenerate an expanding beam 446 of charged particles, in particularelectrons. The expanding charged particle beam 446 is collimated by acollimator lens 447. The collimated charged particle beam then fallsonto an aperture array 448, which generates multiple beamlets, inparticular an array of substantially parallel beamlets 449.

The array of multiple substantially parallel beamlets 449 is directed tothe subsequent module 442, comprising a deflector array 450, alsoreferred to as beamlet blanker array. The deflector array 450 comprisesa deflector for each one of said beamlets 449. Each deflector isarranged to deflect an individual beamlet 449 or to let said individualbeamlet 449 pass without deflection. In the subsequent lower module 443a beam stop array 451 is arranged, provided with an array of apertures.In case an individual beamlet 449 is not deflected by the correspondingdeflector of the deflector array 450, it will pass through thecorresponding aperture of the beam stop array 451. In case an individualbeamlet 449 is deflected by the corresponding deflector of the deflectorarray 450, it is deflected away from the aperture of the beam stop array451 and impinges on the part of the beam stop array 451 surrounding saidaperture. The combination of deflection array 450 and beam stop array451 effectively allows switching the individual beamlets 449 on or off.

The beamlets 449 which pass the aperture array 451 are directed towardsa lens array 452 in the subsequent lower module 444. The lens array 452comprises an array of lenses for focusing the charged particle beamlets449 onto the surface of the substrate 5. This module 444 may alsocomprise one or more deflectors for scanning the array of beamlets 449over the surface of the substrate 5. By suitably addressing thedeflector array 450 and by scanning the beamlets 449 over the surface ofthe substrate 5, a pattern can be written on the surface of thesubstrate 5.

FIG. 4B shows an example of an exposure apparatus for an opticallithography system 540 which is arranged on the exposure apparatus frame41.

The upper module 541 comprises a light source 545 arranged to generate alight beam 546 which is directed to an optical system 547, 548 which isarranged to homogenize and to collimate the light beam 549. Thecollimated and homogenized light beam 549 is directed to the subsequentmodule 542 which comprises a mask 550. The mask 550 is illuminated bythe light beam 549, and the transmitted light is directed to thesubsequent lower module 543. The mask 550 can be a mask having a fixedpattern or a mask having switchable elements which can be switched to atransparent state or an opaque state in order to provide a changeablepattern. In the module 543 a lens system 551, 552 is arranged to imagethe mask 550 onto the surface of the substrate 5. Accordingly thepattern of the mask 550 is projected onto the surface of the substrate5.

FIG. 4C shows an example of an exposure apparatus for an electronmicroscope 640 which is arranged on the exposure apparatus frame 41. Theelectron microscope 640 comprises an electron source 645 arranged togenerate an electron beam 646 which is directed to an optical system647, 648 arranged to direct the electron beam 649 towards severalelectron lenses 650, 651. The electron lenses are arranged to focus theelectron beam 549 onto the surface of the substrate 5. The electronmicroscope 640 is usually provided with one or more deflectors forscanning the electron beam 649 over the surface of the substrate 5.

When the electron beam 649 impinges on the surface of the substrate 5,the interaction of the electrons and the material of the surface of thesubstrate 5 may cause e.g. scattering of the electrons, generation ofsecondary electrons and/or the generation of light. The electronmicroscope 649 is provided with sensors 652 which can detect thescattered electrons, secondary electrons and/or generated light. Byscanning the electron beam 649 over the surface of the substrate 5 anddetecting the scattered electrons, secondary electrons and/or generatedlight, the surface of the substrate 5 can be mapped and/or imaged.

The above description is included to illustrate the operation of thepreferred embodiments and is not meant to limit the scope of theinvention. From the above discussion, many variations will be apparentto one skilled in the art that would yet be encompassed by the spiritand scope of the present invention.

The embodiments may further be described using the following clauses:

1. A mechanical adjustment assembly for adjusting a position of a firstpart of a series of mechanically linked components with respect to asecond part of a series of mechanically linked components,

wherein said mechanical adjustment assembly comprises a first bellows, asecond bellows and a conduit, wherein the conduit interconnects saidfirst bellows and said second bellows for forming a hydraulic system,

wherein said first bellows is arranged between said first part and saidsecond part of said series of mechanically linked components, whereinthe second bellows is arranged spaced apart from said first bellows, andwherein the first bellows is arranged to be actuated by said secondbellows.

2. The mechanical adjustment assembly according to clause 1, wherein thesecond bellows is provided with a drive unit, arranged to compress orexpand the second bellows for actuating the first bellows, wherein saiddrive unit preferably comprises a motor.

3. The mechanical adjustment assembly according to clause 1 or 2,wherein the system comprises at least one sensor for measuring aposition of said first part with respect to said second part of saidseries of mechanically linked components or a change in position of thefirst part of said series of mechanically linked components with respectto the second part of said series of mechanically linked components.

4. A substrate exposure system comprising a mechanical adjustmentassembly according to any one of clauses 1-3, said substrate exposuresystem further comprising:

a frame,

a substrate support module for supporting a substrate, and

an exposure apparatus, carried by said frame and arranged for exposingthe substrate to exposure radiation, wherein said first part of saidseries of mechanically linked components comprises the exposureapparatus, and said second part of said series of mechanically linkedcomponents comprises the substrate support module.

5. Method for adjusting a position of a first part of a series ofmechanically linked components with respect to a second part of a seriesof mechanically linked components, comprising:

providing a mechanical adjustment assembly comprising a first bellows, asecond bellows and a conduit, wherein the conduit interconnects saidfirst bellows and said second bellows for forming a hydraulic system,

arranging said first bellows between said first part and said secondpart of said series of mechanically linked components,

arranging the second bellows spaced apart from said first bellows, and

actuating the second bellows, thereby causing actuation of the firstbellows, such as to adjust the position of the first part ofmechanically linked components with respect to the second part of theseries of mechanically linked components.

6. Method according to clause 5, further comprising controlling theactuating of the second bellows based on signals from at least onesensor measuring a position of said first part with respect to saidsecond part of said series of mechanically linked components or a changein position of the first part of said series of mechanically linkedcomponents with respect to the second part of said series ofmechanically linked components.

7. Substrate exposure system comprising:

a frame,

a substrate support module for carrying a substrate, which substratesupport module is connected to said frame,

an exposure apparatus, wherein the exposure apparatus is carried by saidframe and is arranged for exposing the substrate carried by thesubstrate support module, and

an adjustment assembly for adjusting the position of the exposureapparatus with respect to the substrate support module, wherein theadjustment assembly comprises a hydraulic actuator, a hydraulicgenerator and a conduit, wherein the conduit interconnects saidhydraulic actuator and said hydraulic generator for forming a hydraulicsystem,

wherein the exposure apparatus, the frame, the adjustment assembly andthe substrate support module are arranged as parts of a series ofmechanically linked components, wherein said series of mechanicallylinked components comprises a first part comprising at least theexposure apparatus, and a second part comprising at least the substratesupport module, and wherein said hydraulic actuator is arranged betweensaid first part and said second part of said series of the mechanicallylinked components.

8. Substrate exposure system according to clause 7, wherein saidhydraulic actuator comprises a first bellows.

9. Substrate exposure system according to clause 7 or 8, wherein saidhydraulic generator comprises a second bellows.

10. Substrate exposure system according to clause 9, wherein the secondbellows is provided with a drive unit, preferably a mechanical lineardrive unit, wherein the drive unit is arranged to compress or expand thesecond bellows for actuating the first bellows.

11. Substrate exposure system according to clause 10, wherein the driveunit comprises a motor, preferably a stepper motor.

12. System according to any one of the clauses 7-11, wherein the systemcomprises at least one sensor for measuring a position of said firstpart with respect to said second part of said series of the mechanicallylinked components or a change in position of the first part of saidseries of mechanically linked components with respect to the second partof said series of mechanically linked components.

13. System according to clause 12, wherein the sensor is arranged formeasuring a position of the exposure apparatus with respect to a framesegment which is part of the second part of said series of mechanicallylinked components or a change in position of the exposure apparatus withrespect to a frame segment which is part of the second part of saidseries of mechanically linked components.

14. Substrate exposure system according to any one of the clauses 7-13,wherein the exposure apparatus is moveably connected to the frame bymeans of at least one spring element, wherein the first part of saidseries of mechanically linked components comprises said spring element,and

wherein the hydraulic actuator is arranged between the frame and saidspring element.

15. Substrate exposure system according to any one of clauses 7-12,wherein the hydraulic actuator is arranged between the frame and thesubstrate support module.

16. Substrate exposure system according to any one of clauses 7-15,wherein hydraulic actuator is arranged for moving the exposure apparatuswith respect to the substrate support module, preferably for moving theexposure apparatus with respect to the substrate support module in asubstantially vertical direction.

17. Substrate exposure system according to any one of the clauses 7-16,further comprising a housing, wherein the exposure apparatus and thesubstrate support module are at least partially arranged inside saidhousing, wherein the hydraulic actuator is arranged inside said housingand the hydraulic generator is arranged outside said housing.

18. Substrate exposure system according to clause 17, wherein saidhousing is arranged to function as a vacuum chamber, wherein the housingis coupled to a vacuum pump for, in use, creating a vacuum or a reducedpressure inside said housing, preferably wherein the hydraulic actuatoris vacuum compatible.

19. Substrate exposure system according to any one of clauses 7-18,comprising three adjustment assemblies, preferably wherein said threeadjustment assemblies are arranged in a triangular configuration aroundsaid exposure apparatus and/or said substrate support module.

20. Substrate exposure system according to any one of clauses 7-19,wherein the system is a lithography system and wherein the exposureapparatus comprises an optical column of said lithography system.

21. Substrate exposure system according to any one of clauses 7-20,wherein the exposure apparatus comprises a charged particle beam opticalcolumn, preferably a multi-beam charged particle optical column.

22. A method for adjusting the position of the exposure apparatus withrespect to the substrate support module in a substrate exposure systemaccording to any one of clauses 7-21, wherein the method comprises thestep of: driving the hydraulic generator for actuating the hydraulicactuator which provides a change in position of the said first part withrespect to said second part of said series of the mechanically linkedcomponents.

23. Method according to clause 22, wherein the method further comprisingthe step of:

measuring a position of said first part with respect to said second partof said series of the mechanically linked components or measuring achange in position of the said first part with respect to said secondpart of said series of the mechanically linked components.

24. Method according to clause 23, wherein the method further comprisingthe steps of:

-   -   generating a control signal in accordance with said measured        position or change in position, and    -   driving the hydraulic generator in accordance with said control        signal.

1. A mechanical adjustment assembly for adjusting a position of a firstpart of a series of mechanically linked components with respect to asecond part of a series of mechanically linked components, wherein saidmechanical adjustment assembly comprises a first bellows, a secondbellows and a conduit, wherein the conduit interconnects said firstbellows and said second bellows for forming a hydraulic system, whereinsaid first bellows is arranged between said first part and said secondpart of said series of mechanically linked components, wherein thesecond bellows is arranged spaced apart from said first bellows, andwherein the first bellows is arranged to be actuated by said secondbellows.
 2. The mechanical adjustment assembly according to claim 1,wherein the second bellows is provided with a drive unit, arranged tocompress or expand the second bellows for actuating the first bellows,wherein said drive unit preferably comprises a motor.
 3. The mechanicaladjustment assembly according to claim 1, wherein the system comprisesat least one sensor for measuring a position of said first part withrespect to said second part of said series of mechanically linkedcomponents or a change in position of the first part of said series ofmechanically linked components with respect to the second part of saidseries of mechanically linked components.
 4. (canceled)
 5. Method foradjusting a position of a first part of a series of mechanically linkedcomponents with respect to a second part of a series of mechanicallylinked components, comprising: providing a mechanical adjustmentassembly comprising a first bellows, a second bellows and a conduit,wherein the conduit interconnects said first bellows and said secondbellows for forming a hydraulic system, arranging said first bellowsbetween said first part and said second part of said series ofmechanically linked components, arranging the second bellows spacedapart from said first bellows, and actuating the second bellows, therebycausing actuation of the first bellows, such as to adjust the positionof the first part of mechanically linked components with respect to thesecond part of the series of mechanically linked components.
 6. Methodaccording to claim 5, further comprising controlling the actuating ofthe second bellows based on signals from at least one sensor measuring aposition of said first part with respect to said second part of saidseries of mechanically linked components or a change in position of thefirst part of said series of mechanically linked components with respectto the second part of said series of mechanically linked components. 7.Substrate exposure system comprising: a frame, a substrate supportmodule for carrying a substrate, which substrate support module isconnected to said frame, an exposure apparatus, wherein the exposureapparatus is carried by said frame and is arranged for exposing thesubstrate carried by the substrate support module, and an adjustmentassembly for adjusting the position of the exposure apparatus withrespect to the substrate support module, wherein the adjustment assemblycomprises a hydraulic actuator, a hydraulic generator and a conduit,wherein the conduit interconnects said hydraulic actuator and saidhydraulic generator for forming a hydraulic system, wherein the exposureapparatus, the frame, the adjustment assembly and the substrate supportmodule are arranged as parts of a series of mechanically linkedcomponents, wherein said series of mechanically linked componentscomprises a first part comprising at least the exposure apparatus, and asecond part comprising at least the substrate support module, andwherein said hydraulic actuator is arranged between said first part andsaid second part of said series of the mechanically linked components,preferably the hydraulic actuator is arranged between the frame and thesubstrate support module.
 8. Substrate exposure system according toclaim 7, wherein said hydraulic actuator comprises a first bellows. 9.Substrate exposure system according to claim 7, wherein said hydraulicgenerator comprises a second bellows, preferably the second bellows isprovided with a drive unit, preferably a mechanical linear drive unit,wherein the drive unit is arranged to compress or expand the secondbellows for actuating the first bellows, the drive unit preferablycomprises a motor, preferably a stepper motor.
 10. (canceled) 11.(canceled)
 12. Substrate exposure system according to claim 7, whereinthe system comprises at least one sensor for measuring a position ofsaid first part with respect to said second part of said series of themechanically linked components or a change in position of the first partof said series of mechanically linked components with respect to thesecond part of said series of mechanically linked components. 13.Substrate exposure system according to claim 12, wherein the sensor isarranged for measuring a position of the exposure apparatus with respectto a frame segment which is part of the second part of said series ofmechanically linked components or a change in position of the exposureapparatus with respect to a frame segment which is part of the secondpart of said series of mechanically linked components.
 14. Substrateexposure system according to claim 7, wherein the exposure apparatus ismoveably connected to the frame by means of at least one spring element,wherein the first part of said series of mechanically linked componentscomprises said spring element, and wherein the hydraulic actuator isarranged between the frame and said spring element.
 15. (canceled) 16.Substrate exposure system according to claim 7, wherein hydraulicactuator is arranged for moving the exposure apparatus with respect tothe substrate support module, preferably for moving the exposureapparatus with respect to the substrate support module in asubstantially vertical direction.
 17. Substrate exposure systemaccording to claim 7 claim, further comprising a housing, wherein theexposure apparatus and the substrate support module are at leastpartially arranged inside said housing, wherein the hydraulic actuatoris arranged inside said housing and the hydraulic generator is arrangedoutside said housing.
 18. Substrate exposure system according to claim17, wherein said housing is arranged to function as a vacuum chamber,wherein the housing is coupled to a vacuum pump for, in use, creating avacuum or a reduced pressure inside said housing, preferably wherein thehydraulic actuator is vacuum compatible.
 19. Substrate exposure systemaccording to claim 7, comprising three adjustment assemblies, preferablywherein said three adjustment assemblies are arranged in a triangularconfiguration around said exposure apparatus and/or said substratesupport module.
 20. Substrate exposure system according to claim 7,wherein the system is a lithography system and wherein the exposureapparatus comprises an optical column of said lithography system. 21.Substrate exposure system according to claim 7, wherein the exposureapparatus comprises a charged particle beam optical column, preferably amulti-beam charged particle optical column.
 22. A method for adjustingthe position of the exposure apparatus with respect to the substratesupport module in a substrate exposure system according to claim 7,wherein the method comprises the step of: driving the hydraulicgenerator for actuating the hydraulic actuator which provides a changein position of the said first part with respect to said second part ofsaid series of the mechanically linked components.
 23. Method accordingto claim 22, further comprising: measuring a position of said first partwith respect to said second part of said series of the mechanicallylinked components or measuring a change in position of the said firstpart with respect to said second part of said series of the mechanicallylinked components.
 24. Method according to claim 23, further comprising:generating a control signal in accordance with said measured position orchange in position, and driving the hydraulic generator in accordancewith said control signal.